unreasonable

unreasonable — adjective

1. describes a person's behaviour, a demand, a rule, or a price that goes beyond wh

1.adjectiveB1
Definition

describes a person's behaviour, a demand, a rule, or a price that goes beyond what most people would consider fair, sensible, or normal; expecting too much from others

Example

The landlord's demand for an extra month of deposit seemed unreasonable to the tenants.

collocation: unreasonable demand / unreasonable price

Otis's father was being unreasonable when he refused to listen to any explanation.

pattern: be unreasonable (describing a person's behaviour)

Common collocations
  • completely unreasonable
  • totally unreasonable
  • unreasonable demand
  • unreasonable price
  • unreasonable request
  • unreasonable behaviour
  • unreasonable person
Synonyms
  • absurd

    stronger than 'unreasonable'; suggests something is laughably or ridiculously unreasonable

  • excessive

    focuses specifically on quantity, degree, or amount being too high

  • irrational

    applies to thoughts, fears, or beliefs that lack logical basis, rather than to demands or rules that are unfair

Antonyms
  • reasonable

    the direct opposite; describes what is fair, sensible, and based on good judgment

  • fair

    focuses on justice and equality rather than logic

  • sensible

    describes practical, wise decisions rather than fairness

Grammar Patterns

it + be + unreasonable + to-infinitive

be + unreasonable + of + person + to-infinitive

unreasonable + noun (demand/price/request)

Usage Note

Common in negative evaluations of rules, prices, demands, and people's behaviour. Frequently used with intensifying adverbs such as 'completely', 'totally', or 'quite'.

Common Mistakes

The price is unreasonable expensive.
The price is unreasonably expensive.
'unreasonable' is an adjective; use the adverb form 'unreasonably' before another adjective.
His fear of darkness is unreasonable.
His fear of darkness is irrational.
use 'irrational' for fears or feelings that lack logic; use 'unreasonable' for demands, rules, or behaviour that is unfair or excessive.

Word family

Synonym discussion

Sense: adjective/1

Unreasonable, excessive, and irrational all describe something that goes beyond normal limits, but each has a different focus. Unreasonable is the broadest word — it covers demands, rules, prices, or behaviour that are unfair or lack sensible judgment: 'The landlord's request was unreasonable.' Excessive zeroes in on quantity or degree: 'She spent an excessive amount on shoes.' Irrational applies to thoughts, fears, or actions that do not follow logic: 'His irrational fear of elevators made him take the stairs.' Use unreasonable when fairness or sensible limits are the main issue, excessive when the amount is too high, and irrational when the thinking itself makes no sense. A price can be both unreasonable and excessive, but only a feeling can be called irrational.

absurd ↗excessive ↗irrational

Common collocations

Nouns

Adverbs

Phrases

  • it is unreasonable to
  • something is unreasonable of someone

Prepositions

  • unreasonable in
  • unreasonable about

Etymology

LatinFrenchEnglish

Formed in English by adding the prefix 'un-' (meaning 'not') to 'reasonable', which traces back through Old French 'raisonable' to Latin 'rationabilis', meaning 'having the power to reason'.